Conventionally, a standalone-type public display device which displays departure information by using a large display has been set in a departure terminal of an airport. If it is an airport of, for example, an English-speaking area, such a public display device is displayed in English as a display language. In order to support users of a plurality of different linguistic areas, some devices prepare buttons for a plurality of languages so that display is switched to the display of the language corresponding to the pressed button. In display control of contents such as movies corresponding to a plurality of languages, there are: a mechanism which carries out display in the language corresponding to a user according to setting by the user or the information embedded in a device, a device in which a plurality of language-corresponding buttons are provided and display is carried out in a language when the language is selected, and a device which displays embedded captions of a plurality of languages by time division.    Patent Document 1: Japanese Patent Application Laid-Open (kokai) No. H11-327725    Patent Document 2: International Publication No. WO-00-048082    Patent Document 3: Japanese Patent Application Laid-Open (kokai) No. 2003-345325    Patent Document 4: Japanese Patent Application Laid-Open (kokai) No. 2004-180097
However, in such conventional information display systems corresponding to a plurality of languages, when a particular user is using it, the display is in a particular language desired by the user, and the display cannot be understood if a user of a different language is watching it. Particularly, in the case of a public display device of, for example, an airport terminal, a plurality of users of different linguistic areas watch departure information, and there is a problem that, when the display is in the language of particular users, the information cannot be read at all if there is another user of a different linguistic area who is watching the display. In expectation of people of a plurality of linguistic areas who use the public display, displaying captions of a plurality of languages by time division is conceivable. However, there are problems that, when there are many languages to be supported, it takes time until the display appears in the language of the user, which is desired to be watched by the user; and, when the number of displayed languages is increased, the displayed time at a time has to be shortened. Furthermore, also in the case in which a language is selected by a button and also in the case in which captions are displayed by time division, there are a problem that the number of supported languages is practically limited and a problem that there is a lack of convenience as a public display device of, for example, an airport terminal where users of many linguistic areas come and go.